Air-oil separator for a crankcase ventilation system in an internal combustion engine

An air-oil separator for an automotive engine having a crankshaft, a crankcase housing the crankshaft, and an air induction system, comprising:

• a housing;
• an inlet at a lower end of said housing and being in fluid communication with the crankcase, with said inlet receiving a stream of blowby gas contained within said crankcase, and with said inlet having an outer cylindrical tube defining an axis and an inner cylindrical tube substantially coaxial with said outer tube, said inner tube having a length less than the length of the outer tube when measured along said axis, said outer tube having an outer edge lying in a plane substantially perpendicular to said inlet axis, said inner tube having an outer edge lying in a plane intersecting said outer edge plane of said outer tube, such that, when in use, said blowby gas in said inlet swirling in a cyclone thereby forcing at least a portion of entrained oil to move outward and impinge on said outer tube and drain into the crankcase;
• a partially enclosed baffle within said housing, said baffle having a baffle inlet at one end thereof and a baffle outlet at another end thereof such that, when in use, at least a portion of oil entrained in said blowby gas impinges on interior walls of said baffle and drains to said inlet;
• an outlet chamber within said housing and being in fluid communication with said baffle outlet, said outlet chamber having a volume of space substantially greater than the volume of space in said baffle such that, when in use, blowby gas entering said outlet chamber decreases in velocity, thereby allowing any further entrained oil in said blowby gas to fall out of said stream and drain into said baffle;
• and,
• an outlet at an upper end of said housing and being in fluid communication with said outlet chamber for introducing the oil-free gas to the air induction system.

An air-oil separator for an automotive engine having a crankshaft, a crankcase housing the crankshaft, and an air induction system, comprising:

• a housing;
• a cyclonic section at a lower end of said housing and being in fluid communication with the crankcase, with said cyclonic section receiving a stream of blowby gas contained within said crankcase such that, when in use, said blowby gas in said cyclonic section swirls in a cyclone thereby forcing at least a portion of entrained oil to move outward and drain into the crankcase;
• an impinging section within said housing and being arranged in series relationship relative to said cyclonic section, said impinging section having an inlet at one end thereof and an outlet at another end thereof such that, when in use, at least a portion of oil entrained in said blowby gas coalesces on said impinging section and drains to said cyclonic section;
• a venturi section within said housing and being in fluid communication with and arranged in series relationship relative to said impinging section, with said venturi section having a volume of space substantially greater than a volume of space in said impinging section such that, when in use, blowby gas entering said venturi section decreases in velocity, thereby allowing any further entrained oil in said blowby gas to fall out of said stream and drain into said impinging section;
• and,
• an outlet at an upper end of said housing and being in fluid communication with said venturi section for introducing the oil-free gas to the air induction system.